Human Embryonic Stem Cell‐Derived Immunity‐And‐Matrix‐Regulatory Cells Attenuate Pulmonary Fibrosis via MMP1 ‐Mediated Collagen Degradation

Currently, no targeted therapy exists for idiopathic pulmonary fibrosis (IPF). The hallmark pathological feature of excessive extracellular matrix (ECM) deposition severely undermines the efficacy of mesenchymal stem cell (MSC)-based treatments. While existing MSC therapeutic strategies primarily focus on modulating inflammation in early stages, they have not yet established precise interventions addressing the core pathological mechanism-ECM dysregulation. Previous studies demonstrated the therapeutic potential of human embryonic stem cell (hESCs)-derived immunity-and-matrix-regulatory cells (IMRCs) in lung injury and fibrosis models. However, the critical biomarkers and underlying mechanisms mediating IMRCs' efficacy in IPF remain poorly understood. In this study, we generated MMP1 knockout IMRCs (IMRCs-MMP1 KO) using CRISPR-based gene editing. We then characterized whether MMP1 ablation affected key properties of IMRCs, including cell morphology, proliferation, migration, marker protein expression, transcriptomic profile, and cytokine secretion. Subsequently, the ability of IMRCs-MMP1 KO to degrade collagen was tested using in vivo and in vitro pulmonary fibrosis models. MMP1 knockout was successfully achieved and did not compromise typical IMRC characteristics or impair their immunomodulatory capacity. However, MMP1 deficiency significantly attenuated the ability of IMRCs to degrade TGF-β1-induced collagen I deposition in A549 cells. Importantly, wild-type IMRCs demonstrated superior therapeutic efficacy in ameliorating bleomycin-induced lung injury and fibrosis in mice compared with IMRCs-MMP1 KO. Furthermore, IMRCs exhibited significantly greater capability to directly degrade the pericellular collagen I and modulate fibroblasts' activation progression within fibrotic lung tissues in a MMP1-dependent manner. In summary, our data establish that MMP1 plays an essential functional role in IMRC-mediated attenuation of PF. MMP1 thus represents a key therapeutic biomarker for IMRC-based treatment. This work provides a foundation for developing stem cell therapies tailored to the pathological features of IPF, potentially enabling adaptive treatment strategies.